It is generally desirable that microelectronic devices, such as sensors and integrated circuits, are required to be thin in order to be competitive in the consumer market place. Some microelectronic devices combine what is traditionally a two-chip design: a micromachined device, such as a g-cell sensor (accelerometer), and an integrated circuit, such as an ASIC (Application Specific Integrated Circuit). Many prior art devices have included the use of a capping component bonded to a semiconductor wafer component for protection of the micromachined devices formed thereon.
One possible means of achieving the required thinness for these component parts is through wafer thinning. During fabrication, the semiconductor wafer and the capping component undergo separate wafer thinning processes prior to assembly. Often these wafer thinning processes result in thin components that are susceptible to damage during the remaining fabrication processes and handling.
As an example, during current fabrication techniques, wafer thinning of the substrate, or a sensor component, is completed prior to release of the movable sensor structure. It is very difficult to handle these thinned sensor components reliably without damaging the sensor structure. Wafer thinning and through holes for electrically connecting the sensor structure to external circuitry are formed in the capping component prior to bonding of the sensor component and the capping component. Physical wafer thinning processes, such as chemical or mechanical grinding, cannot be performed after the through hole openings are formed on the capping component due to the susceptibility of the wafer to breakage during this process. Due to these thinning and through hole fabrication steps, it is difficult to handle the capping component prior to bonding of the two components into a combined wafer structure.
Accordingly, it would be desirable to provide for method of forming a microelectronic device utilizing a novel thinning process, thereby reducing the risk of wafer breakage during fabrication, that is compatible with standard semiconductor processes. The novel thinning method provides for a strong bonded wafer structure and provides for a device that is better able to withstand the manufacturing process. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.